I live with my boyfriend and we split the cost of the mortgage and bills but my name isnt on the house or bills or anything so what should i put for monthly rent?
There is not a rent deduction or credit on your Federal return. If your state has anything for renters you will be prompted to enter your rent info when you complete your state return. As far as I know, the states that have anything for rent are Arizona, California, Connecticut, Hawaii, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Jersey, Rhode Island, Vermont, and Wisconsin.
And... if you are entering your monthly "rent" on a state return, your BF has to claim the rental income he is receiving on his own tax returns--federal and state. Your arrangement sounds more like cost-sharing than a rental situation, no?